Hydrocephalus due to membranous obstruction of the fourth ventricle.
D000293:Adolescent; D000328:Adult; D002551:Cerebral Ventricle Neoplasms / Q000175:diagnosis; D002552:Cerebral Ventricles / Q000002:abnormalities* / Q000473:pathology; D014695:Cerebral Ventriculography; D002648:Child; D003937:Diagnosis, Differential; D004453:Echoencephalography; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology*; D007223:Infant; D008297:Male; D008566:Membranes